Portable hoisting-machine



L. T. PYOTT.

1 PORTABLE HOISTING MACHINE.

Patented Jan.23, 1883.

152mm for.

715175106868 7. 11 @MLWM &4 mfla (No M bdel.) 2 Sheets-Sheet 2.

L. T. PYOTT.

PORTABLE HOISTING MACHINE. No. 271,115 Patenggd Jan.23, 1883.

ff. 15 wwm/ w, W?

UNITED STATES PATENT OFFIcE.

LOUIS T. PYO'IT, OF PHILADELPHIA, PENNSYLVANIA.

PORTABLE HOISTING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 271,115, dated January 'i 3, 1883.

I I Application filed July 13, 1882. (No model.)

To all whom it may concern:

Beit known that I, LoUIs T. PYOTT, of the city of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Hoisting-lilachines, of which the following is a specification.

This invention relates to those forms of portable hoistingmachines in which a screw and worm gear journaled in a hanging frame and driven by an endless handchain and sheave rotate a sprocket or chain wheel carrying the lifting-chain.

The improvement consists, first, in male ing the worm-wheel in halves and in connection with the lifting-sheaves, as hereinafter described.

The improvement consists, further, in the construction of the frame and bearing for the worm or screw, affording a very simple, strong, and readily-accessible means of suspension of the working parts.

Theimprovementconsists, further, in the use of the form of worm or screw hereinafter described,working in a worm-wheel, with teeth corresponding in shape as applied specially to these machines.

In the accompanying drawings, in which similar letters of reference indicate like parts, Figure 1 is a side elevation and partial vertical section through the center of the machine. Fig. 2 is a plan view of the same, and Fig. 3 is an end elevation and half vertical section.

The uorm-wheel-A is made in halves, and cast in connection with the chain-sheaves, the whole being contained within the hanger or frame D. This renders the machine safe from overriding of either lifting-chain, and in case either chain should break the load would be carried by the other almost in a direct line to the point of suspension, thus avoiding any great side strain.

Forming the worm-wheel in halves, with intervening space between the bottom of the teeth, as shown, serves to retain the lubricator in contact with the worm or screw, and also gives adecided advantage in casting the wheel.

The two halves of worm-wheel A are held securely together by the tube B, riveted at each end. Said tube B revolves loosely upon the shaft (3, which is carried in the frame D. Said shaft 0 has a head upon one end and a nut upon the other, and binds the frame D securely together. The frame D is made in one piece,

and carries the weight in adirect line from the center ofthe sheaves to the pointof'suspension.

The worm E and shaft are carried in the bearing F, which bearing F is slipped up into frame D from below and held by two screws, as shown. The worm E is readily removed by taking out loose bushing G. Said worm E has the faces of the thread on the lifting side out so as to present a square thrust-surface to the worm-wheel. This form of thread has special advantages in this class of machines, as all of the work comes upon one side of the thread. The back of the thread is angled, as shown, making it very wide at the base, and in consequence very strong.

H is the hand-chain sheave common to this class of machines.

Having thus described my invention, what I claim is 1. In a pulley-hoist, a worm-wheel formed in two equal parts, substantially as: shown and described.

2. In a portable pulley-hoist, a worm-wheel formed in two equal parts, with a chain-sheave formed upon or attached to each of said parts, as and for the purpose specified.

3. In a portable pulley-hoist, a worm-wheel formed in two equal parts, with intervening spaces between the parts of the teeth, substantially as set forth.

4. In a portable pulley-hoist, the divided worm-wheel A, loose collar B, and shaft 0, in

combination with the frame D, formed in one A piece, and provided with a supporting-hook at tached to it in a nearly direct line above the point of suspension,'as and for the purpose specified.

5. In a portable pulley-hoist, the frame D and the removable bushing G, in combination with the worm-shaft carrying worm E, substantially as set forth.

6. In a portable pulley-hoist, the frame D, bushing G, and bearing F,in combination with the divided worm-wheel A, loose collar B, shaft (1, and the worm E, having a straight thrustface and a tapering or inclined rear face, as set forth.

LOUIS T. PYOTT. 

